Slip stop friction sub

ABSTRACT

A device, system, and/or method for hanging a casing in a borehole operation are provided. A gripping feature may be included on an inner surface of a larger casing. Then, a smaller casing is positioned within the larger casing, and the outer diameter of the smaller casing or the hanging mechanism is expanded to contact the larger casing&#39;s gripping feature. The result is a secure engagement between the two casings. This gripping feature may comprise grooves cut into the inner surface of the larger casing wherein the grooves may have a groove density, an uphole groove angle, a downhole groove, an orientation, and other features that improve the engagement between the two casings.

FIELD OF THE INVENTION

The invention relates to borehole casings and liners, and the invention specifically relates to liners that are securely hung from other casings or liners.

BACKGROUND OF THE INVENTION

A casing is a pipe that is inserted into a borehole and is typically cemented in place. Casings often extend all the way back to the wellhead and may have various diameters and lengths for a variety of reasons. Casings maintain the stability of the borehole and provide a controlled space for production equipment to operate, for example, to extract natural resources from the earth. Casings also protect the environment from the production equipment and related byproduct inside of the casings. In one example, environmental regulations mandate the preservation of fresh water zones, and casings protect the fresh water zones from production materials. Casings also provide a location to install a blowout preventer, which is a large valve that serves as a fail-safe against catastrophic pressure and fluid flow out of the borehole. Multiple casings may be nested within each other to provide various functions. Different types of casings include conductor casings, surface casings, intermediate casings, and production casings.

A liner is a type of casing that may not extend back to the wellhead. Rather, a liner is typically hung above the shoe of another casing or liner. Liners help reduce cost and improve hydraulic performance when drilling the borehole deep into the earth. The process or method by which a liner is hung is a setting sequence, and there are several setting sequences to hang a liner. In one example, the liner is positioned at least partially within a larger diameter liner or casing. A setting device or hanging mechanism is positioned at least partially within the liner. The setting device expands at least a portion of the liner such that the outer diameter of the liner contacts the inner diameter of the other liner or casing to create an interference or friction fit between the two components.

However, the setting sequence may also introduce some problems. Due to allowed tolerances from governing bodies, the setting sequence may result in a sub-optimal engagement between the liner and the other casing or liner. The smaller diameter liner, anchoring device, and other components may slide down the borehole or move up the borehole due to pressure, geologic conditions, improper tool release, or other well conditions that were pre-existing or induced by the drilling, completion/workover, or intervention process. The sub-optimal engagement and resulting consequences may place unforeseen stress on equipment that results in damaged assets, a loss of well control, a redesign of the drilling operation and well, a completion/workover, an intervention, or a modification of directional or bottom hole locations. Therefore, a secure engagement between the liner and the other liner or casing is paramount to the success of the drilling operation.

Some prior art devices have attempted to address the liner setting sequence and the engagement between the liner and the other liner or casing. For example, U.S. Pat. Nos. 7,537,060; 7,540,329; 7,581,595; 7,604,061; and 8,002,044, which are hereby incorporated by reference in their entireties, describe a liner hanging mechanism where fingers on a liner engage a slip of a casing, which in turn causes gripping features to sink into the inner diameter surface of the outer liner or casing. However, the complex nature of these devices adds cost, and the device relies on moving spring-biased gripping features, which increase the chances of failure. If the liner's fingers fail to engage, if the casing's slip fails to move, and/or if the spring-biased gripping feature fails to release, then the setting sequence will result in a sub-optimal engagement between the liner and the casing.

Another type of liner hanging mechanism uses gripping features that expand from the liner outwards to sink into the inner diameter of another casing or liner. An example of such a device may be found in U.S. Pat. No. 6,877,567, which is hereby incorporated by reference in its entirety. However, again, if the moving parts of this type of liner hanging mechanism fail, then the liner will fall down the bore hole. Other prior art devices may be found in U.S. Pat. Nos. 4,311,194; 4,498,534; 4,580,631; 4,669,538; 5,086,845; 5,499,681; 6,648,075; 6,920,934; 7,048,065; 7,114,573; and 7,546,872, which are hereby incorporated by reference in their entireties.

SUMMARY OF THE INVENTION

It is therefore an aspect of embodiments of the invention to provide a device, system, and/or method for hanging a casing in a borehole, riser, or any other similar drilling operation that provides a secure engagement between the liner and another casing or liner, to prevent movement of the hung liner. One or more gripping features may be disposed on an inner surface of the other casing or liner, wherein the one or more gripping features contribute to a secure engagement between the liner and the other casing or liner.

It is one aspect of embodiments of the invention to provide a device, system, and/or method for hanging a casing in a borehole operation wherein a gripping feature is a plurality of grooves. A setting device or hanging mechanism may expand an outer diameter of a smaller casing such that the smaller casing's outer surface contacts the gripping feature and grooves of a larger casing. This causes the larger casing's grooves to sink into the outer surface of the smaller casing. Thus, the engagement between the two casings is a friction or interference fit with physically interlocking portions, i.e., where the grooves sink into the outer surface of the second casing. This provides a secure engagement to prevent movement between the two casings.

It is another aspect of embodiments of the invention to provide a device, system, and/or method for hanging a casing in a borehole operation wherein a gripping feature comprised of one or more grooves may be defined by parameters including groove depth, gripping feature density, uphole angle, and downhole angle. A groove depth is the distance between a casing's inner diameter and the lowermost portion of the groove, and the groove depth may be limited in some embodiments due to minimum wall thickness requirements. The gripping feature density is the number of grooves per longitudinal distance of the casing's inner surface, and the uphole angle and the downhole angle describe the orientation of a groove's upward face and downward face, respectively.

These parameters may be the same for each groove in a given gripping feature. However, it will be appreciated that in some embodiments, these parameters and other parameters used to describe a groove may vary from groove to groove. For example, the groove depth for grooves in a gripping feature may get progressively deeper or shallower in the uphole or downhole direction of the casing. In another example, the uphole angle, the downhole angle, and the gripping feature density continuously change in one of the uphole or downhole directions of the casing. It will be further appreciated that the variations of these parameters may not be continuous, but rather may be disjointed or random in sequence. Variations of these parameters may change from gripping feature to gripping feature on a given casing.

It is another aspect of embodiments of the invention to provide a device, system, and/or method for hanging a casing in a borehole operation wherein a gripping feature may be comprised of two or more pluralities of grooves. In some embodiments, these pluralities form a criss-crossing pattern. A first plurality of grooves may be oriented along a first angle, and a second plurality of grooves may be oriented along a second angle. In yet other embodiments, the pluralities of grooves may be oriented along a curved line, such as a curve with a constant radius or a curve described by an n-order polynomial.

It is an aspect of embodiments of the invention to provide a device, system, and/or method for hanging a casing in a borehole operation wherein a gripping feature comprises one or more shaped features. In some embodiments, the shaped features are simply the result of grooves being cut, etched, etc. in to the inner surface of the case. In various embodiments, the shaped features are independently created by being cut, etched, etc. In certain embodiments, the shaped feature may be a pyramid, a convex curve, a concave curve, and other geometric shapes.

It is one aspect of embodiments of the invention to provide a device, system, and/or method for hanging a casing in a borehole operation wherein a gripping feature may be formed by a number of processes and/or methods. This includes milling or cutting, knurling, chemical etching, sandblasting, hook-and-loop fastening, etc. These processes and methods may manipulate the material of the casing, but in various embodiments, the gripping feature includes additional components besides the casing material itself. For example, the gripping feature may be treated with a carbide coating, have welded ball bearings, or treated with a spray-on grit.

It is an aspect of embodiments of the invention to provide a device, system, and/or method for hanging a casing in a borehole operation wherein an additional component complements the gripping feature to create a secure engagement between two casings. For example, an adhesive may be included in the recesses of a gripping feature. This adhesive may be pressure or temperature sensitive. Thus, when a setting device or hanging mechanism expands a liner's outer diameter into a gripping feature, the adhesive provides additional bonding between the two casings. In some embodiments, the adhesive comprises two portions that bond when pressed into each other. Pressure sensitive adhesives are often an elastomer compound with a suitable tackifier (e.g., rosin ester), wherein examples of elastomers include, but are not limited to, acrylics, butyl rubber, ethylene-vinyl acetate, natural rubber, nitriles, silicone rubbers, vinyl ethers, and styrene block copolymers such as styrene-butadiene-styrene, styrene-ethylene/butylene-styrene, styrene-ethylene/propylene, and styrene-isoprene-styrene.

It is yet another aspect of embodiments of the invention to provide a device, system, and/or method for hanging a casing in a borehole operation wherein a casing with a gripping feature is used in conjunction with existing devices, systems, and/or methods. An example of one system may be found in U.S. Pat. No. 8,100,188, which is hereby incorporated by reference in its entirety. In the '188 patent, a hydraulic-powered device drives an expansion portion through a liner to expand the liner's outer diameter, but other methods may be used including mechanical swaging, explosive expansion, memory metal expansion, swellable material expansion, electromagnetic force-driven expansion, etc. The expansion portion may have a frusto-conical portion that expands the liner's outer diameter in one or more passes. The expansion portion may include structures such as wedges or swages.

It is an aspect of embodiments of the invention to provide a device, system, and/or method for hanging a casing in a borehole operation wherein liners and casings may or may not include a lip catch, which is a flange portion of a casing end that aids in the engagement between two casings. Embodiments of the invention may rely on the gripping feature exclusively and not use a lip catch, yet still meet the standards of governing bodies.

One particular embodiment of the present invention is a system for hanging a casing in a borehole operation, comprising a first casing having a wall thickness and an inner surface defining a first partially enclosed volume, the inner surface of the first casing having a gripping feature, wherein the gripping feature extends around at least a portion of an inner perimeter of the inner surface; a second casing having an outer surface with an initial diameter, the second casing is at least partially disposed within the first partially enclosed volume defined by the inner surface of the first casing, wherein the second casing has an inner surface defining a second partially enclosed volume; and a setting tool at least partially disposed within the second partially enclosed volume defined by the inner surface of the second casing, the setting tool adapted to expand at least a portion of the outer surface of the second casing to a final diameter that is larger than the initial diameter, wherein the outer surface of the second casing presses against the gripping feature to secure the second casing to the first casing.

Another particular embodiments of the present invention is a method for hanging a tubular in a borehole operation, comprising (i) providing a first tubular having an inner surface with an inner diameter, wherein a plurality of grooves is positioned on the inner surface of the first tubular; (ii) providing a second tubular having an outer surface and an inner surface, the outer surface having an outer diameter and the inner surface having an inner diameter, wherein the outer diameter of the second tubular is smaller than the inner diameter of the first tubular; (iii) positioning the second tubular at least partially within the first tubular such that the plurality of grooves are positioned over the outer surface of the second tubular; and (iv) pressing a setting tool, which has an outer surface with an outer diameter that is larger than the inner diameter of the second tubular, into the second tubular to deform the second tubular and expand at least a portion of the outer diameter of the second tubular into the plurality of grooves of the first tubular to secure the second tubular to the first tubular. It will be appreciated that embodiments of the present invention may comprise any combination of these steps.

Yet another particular embodiment of the present invention is a tubular for a borehole operation comprising a body extending between a first end and a second end, the body having an inner surface; a first finish on the first end of the body; a second finish on the second end of the body, wherein the second finish is distinct from the first finish; and a plurality of grooves positioned on the inner surface of the body, each groove in the plurality of grooves having an uphole angle and a downhole angle measured from a lateral plane through the body, wherein the downhole angle is nonzero.

In various embodiments of the present invention each groove in the plurality of grooves has an uphole angle and a downhole angle measured from a lateral plane through the first tubular, and wherein the downhole angle is nonzero. Further, in some embodiments, at least one groove in the plurality of grooves has one of a distinct uphole angle and a distinct downhole angle from another groove in the plurality of grooves. In various embodiments, the plurality of grooves comprises a groove density, wherein the groove density is between approximately 0.394 grooves per cm and 15.74 grooves per cm. In certain embodiments, the plurality of grooves extends around an inner perimeter of the inner surface of the first tubular. In various embodiments, the system, method, or device comprises a second plurality of grooves positioned on the inner surface of the body. In some embodiments, a plurality of gripping feature may refer exclusively to grooves or may refer to many different patterns including a knurled pattern. In various embodiments, the gripping feature is a first plurality of grooves and a second plurality of grooves that extend around at least a portion of the inner perimeter of the inner surface of the first casing and form a criss-crossing pattern. In some embodiments, the first plurality of grooves is oriented at an angle relative to the second plurality of grooves, and wherein the first plurality of grooves is oriented perpendicular to the second plurality of grooves.

In some embodiments, a groove of the plurality of grooves comprises a groove depth, wherein the groove depth is between approximately 0.0508 cm and 0.508 cm. In various embodiments, a groove of the plurality of grooves comprises a downhole angle, wherein the downhole angle is between approximately 15° and 90°. In some embodiments, a groove of the plurality of grooves comprises an uphole angle, wherein the uphole angle is between approximately 0° and 90°. In various embodiments, the gripping feature has a length along the longitudinal direction of the inner surface of the first casing, wherein the length of the gripping feature is between approximately 0.635 cm and 1219.2 cm.

These and other advantages will be apparent from the disclosure of the invention(s) contained herein. The above-described embodiments, objectives, and configurations are neither complete nor exhaustive. The Summary of the Invention is neither intended nor should it be construed as being representative of the full extent and scope of the invention. Moreover, references made herein to “the invention” or aspects thereof should be understood to mean certain embodiments of the invention and should not necessarily be construed as limiting all embodiments to a particular description. The invention is set forth in various levels of detail in the Summary of the Invention as well as in the attached drawings and Detailed Description and no limitation as to the scope of the invention is intended by either the inclusion or non-inclusion of elements, components, etc. in this Summary of the Invention Additional aspects of the invention will become more readily apparent from the Detailed Description particularly when taken together with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the disclosure and together with the general description of the disclosure given above and the detailed description of the drawings given below, serve to explain the principles of the disclosures.

FIG. 1 is a side elevation view of a borehole with casings and liners;

FIG. 2A is a perspective view of a casing with a plurality of gripping features according to one embodiment of the invention;

FIG. 2B is a detailed perspective view of the casing in FIG. 2A according to one embodiment of the invention;

FIG. 3 is a cross-sectional elevation view of a casing with a plurality of gripping features according to one embodiment of the invention;

FIG. 4 is a detailed cross-sectional elevation view of the casing in FIG. 3 according to one embodiment of the invention;

FIG. 5 is a cross-sectional view of a gripping feature having a plurality of grooves according to one embodiment of the invention;

FIG. 6 is a detailed cross-sectional view of the plurality of grooves in FIG. 5 according to one embodiment of the invention;

FIG. 7A is a perspective view of a casing with a plurality of gripping features according to one embodiment of the invention;

FIG. 7B is a detailed perspective view of the casing in FIG. 7A according to one embodiment of the invention;

FIG. 8 is a cross-sectional elevation view of a casing with a plurality of gripping features according to one embodiment of the invention;

FIG. 9 is a detailed cross-sectional elevation view of the casing in FIG. 8 according to one embodiment of the invention;

FIG. 10 is a perspective view of a casing with a plurality of gripping features that comprise a plurality of grooves and a casing with a plurality of gripping features that comprise more than one plurality of grooves according to one embodiment of the invention;

FIG. 11 is a detailed perspective view of the two casings in FIG. 10 according to one embodiment of the invention; and

FIG. 12 is a flow chart for a quality assurance process according to one embodiment of the invention.

It should be understood that the drawings are not necessarily to scale, and various dimensions may be altered. In certain instances, details that are not necessary for an understanding of the invention or that render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein.

DETAILED DESCRIPTION

The invention has significant benefits across a broad spectrum of endeavors. It is the Applicant's intent that this specification and the claims appended hereto be accorded a breadth in keeping with the scope and spirit of the invention being disclosed despite what might appear to be limiting language imposed by the requirements of referring to the specific examples disclosed. To acquaint persons skilled in the pertinent arts most closely related to the invention, a preferred embodiment that illustrates the best mode now contemplated for putting the invention into practice is described herein by, and with reference to, the annexed drawings that form a part of the specification. The exemplary embodiment is described in detail without attempting to describe all of the various forms and modifications in which the invention might be embodied. As such, the embodiments described herein are illustrative, and as will become apparent to those skilled in the arts, and may be modified in numerous ways within the scope and spirit of the invention.

Although the following text sets forth a detailed description of numerous different embodiments, it should be understood that the detailed description is to be construed as exemplary only and does not describe every possible embodiment since describing every possible embodiment would be impractical, if not impossible. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims. To the extent that any term recited in the claims at the end of this patent is referred to in this patent in a manner consistent with a single meaning, that is done for sake of clarity only so as to not confuse the reader, and it is not intended that such claim term by limited, by implication or otherwise, to that single meaning.

Various embodiments of the invention are described herein and as depicted in the drawings. The terms “liner” and “casing” may be used interchangeably. Generally, a “liner” is a type of “casing”, but descriptions related to a liner may apply to a casing, and vice versa. In addition, the term “tubular” may be used to refer to a liner, a casing, or another other long, hollow, substantially-cylindrical structure. Further, it is expressly understood that although the figures depict liners, casings, gripping features, and grooves, the invention is not limited to these embodiments.

Now referring to FIG. 1, a side elevation view of a borehole is provided. Casings extend to the surface and are typically cemented in place. Liners are hung from casings and other liners as shown in FIG. 1. The liners are hung above a shoe portion of a casing or a liner. The shoe is the bottom or terminus of a casing or liner. The casings and liners may be nested within each other and have progressively smaller diameters as the drilling operation extends further below the surface of the earth. A setting device or hanging mechanism may be utilized to hang a smaller diameter casing or liner within a larger diameter casing or liner.

Now referring to FIGS. 2A and 2B, perspective views of a casing 2 with a plurality of gripping features 4 are provided. The casing 2 has an inner surface 6 and an outer surface 8, and the plurality of gripping features 4 are equally spaced along the inner surface 6 of the casing. It will be appreciated that in other embodiments, the outer surface 8 of the casing 2 may have one or more gripping features 4, and both the inner and outer surfaces 6, 8 of the casing 2 may have one or more gripping features 4. Further, in embodiments where there are multiple gripping features 4, the spacing may be unequal. For example, the spacing may get progressively smaller or larger in the uphole or downhole direction. In another example, the spacing may be disjointed or random in sequence.

Now referring to FIG. 3, a cross-sectional view of a casing 2 with a plurality of gripping features 4 is provided. Dimensions of the casing 2 are provided, specifically the overall length 10 of the casing 2 and the outer diameter 12 of the casing 2. The dimensions of the casing 2 vary depending on the type of drilling operation, the type of material surrounding the borehole, the depth of the borehole, etc. In some embodiments, the overall length of the casing 2 may be between approximately 0.610 m and 13.72 m, wherein “approximately” implies a variation of +/−10%. Further, it will be appreciated that ranges and other dimensions discussed herein are merely exemplary in nature and embodiments of the invention may have dimensions that are outside of the ranges and dimensions discussed herein. Next, in some embodiments, the outer diameter 12 of the casing 2 is between approximately 11.43 cm and 81.28 cm. The outer diameter 12 of the casing 2 may be several nominal sizes including, but not limited to, 2.667 cm, 3.340 cm, 4.216 cm, 4.826 cm, 5.240 cm, 6.033 cm, 7.303 cm, 8.890 cm, 10.16 cm, 11.43 cm, 12.7 cm, 13.97 cm, 16.83 cm, 17.78 cm, 19.37 cm, 19.69 cm, 21.91 cm, 24.45 cm, 27.31 cm, 29.85 cm, 33.97 cm, 40.64 cm, 47.31 cm, and 50.80 cm.

Now referring to FIG. 4, a detailed cross-sectional view of a casing 2 with a plurality of gripping features 4 is provided. In particular, FIG. 4 shows one end of the casing 2 which may have a variety of finishes on the inner and/or outer surfaces of the casing 2. For example, one end may have a threaded outer surface and the other end may have a threaded inner surface so that a series of casings 2 can be linked together. Thus, in this embodiment, the gripping feature 4 is spaced above the end of the casing 2 by an end offset 14 so that the gripping feature 4 does not interfere with the function of the particular finish of the casing's 2 end. In other embodiments, the end offset 14 may represent an area with a modified gripping feature 4, for example, a gripping feature 4 with less prominent features, and in various embodiments the casing 2 does not comprise an end offset 14 meaning the gripping feature 4 may extend the entire length of the casing 2. In some embodiments, the end offset 14 is between approximately 10.16 and 35.56 cm. In various embodiments, the end offset 14 is approximately 58.06 cm.

Next, the gripping feature 4 shown in FIG. 4 extends along a length 16 of the casing 2 in a longitudinal direction. In some embodiments, the gripping feature length 16 is between approximately 0.635 cm and 1219.2 cm. In various embodiments, the gripping feature length 16 is between approximately 10.16 cm and 304.8 cm. Similarly, there are gaps 18 between gripping features 4 along a longitudinal length of the casing 2. In some embodiments, the gripping feature gap 18 is between approximately 0.635 cm and 609.6 cm. In various embodiments, the gripping feature gap 18 is between approximately 10.16 cm and 152.4 cm.

Now referring to FIG. 5, a cross-sectional view of the casing 2 and the gripping feature 4 is provided wherein the gripping feature is a plurality of grooves 20. The grooves 20 in this embodiment completely extend around a perimeter of the inner surface of the casing 2. It will be appreciated that the grooves 20 and the gripping features 4 may only partially extend around a perimeter of the inner surface of the casing 2. Further, the grooves 20 and gripping features 4 may extend around the perimeter of the inner surface of the casing 2 in discrete sections, leaving some sections of the inner surface of the casing 2 unaltered. It will be appreciated that the grooves 20 may not be linear and may comprise any number of shapes. For example, the grooves 20 may be helical, open-end polygons, curved about a radius of curvature, or curved about a n-order polynomial. In further examples, the grooves 20 may be closed shapes such as squares, rectangles, trapezoids, ellipses, parallelograms, triangles, and circles. Various regions of the casing 2 may be stair-stepped or comprise a scatter patterned groove 20 or plurality of grooves 20.

The casing 2 in FIG. 5 also has an inner diameter 22 which is the diameter of the inner surface of the casing 2. The difference between the inner diameter 22 and the outer diameter 12 is the wall thickness, and depending on various parameters, the wall thickness may be no less than a minimum wall thickness to prevent casings failures and other issues. The American Petroleum Institute (API) provides standards for various drilling technologies, and API Specification 5CT provides standards for casings and liners. See API Specification 5CT, ISO 11960:2004, Petroleum and natural gas industries-Steel pipes for use as casing or tubing for wells (Jan. 1, 2006), which is hereby incorporated by reference in its entirety. For example, referring to Table C.1 of API Specification 5CT, a casing with a nominal outer diameter of 11.43 cm may have a minimum wall thickness from between approximately 5.21 mm to 8.56 mm, depending on various parameters. Thus, in various embodiments, forming the grooves 20 of the gripping features does not remove so much material from the casing 2 that the casing's 2 wall thickness is below the minimum wall thickness in API Specification 5CT. However, in some embodiments, the grooves 20 may not comply with the API Specification 5CT, meaning the casing's 2 wall thickness is below minimum standards specified by the API.

A drift diameter 24 is also provided in FIG. 5. The drift diameter 24 refers to the diameter of an object that should pass through the casing 2 unimpeded. Casings 2 may develop eccentricities that create ovoid-shaped casing diameters. However, there is a limit to this distortion because the interior of the casing 2 must be used for various production functions. Thus, API provides standards for the drift diameter 24 that may be found, for example, in Table C.24 in API Specification 5CT.

Now referring to FIG. 6, a detailed view of the grooves 20 is provided. A groove depth 26 may be limited by governing bodies such as the API because, as noted above, there may be standards for minimum wall thicknesses. In some embodiments, the groove depth 26 is between approximately 0.0254 cm to 1.27 cm. In various embodiments, the groove depth 26 is between approximately 0.0508 cm to 0.508 cm. A groove density 28 is shown in FIG. 6, wherein the groove density 28 refers to the number of grooves 20 in a given longitudinal length of the casing. In some embodiments, the groove density 28 is between approximately 0.0787 grooves per cm to 39.37 grooves per cm. In various embodiments, the groove density 28 is between approximately 0.3937 grooves per cm to 15.75 grooves per cm.

The shape of the grooves 20 is also shown in FIG. 6. Each groove 20 has an uphole angle 32, which is the angle between the upward face of a groove 20 and a lateral plane through the casing. In some embodiments, the uphole angle 32 is between approximately −90° to 180°. In various embodiments, the uphole angle 32 is between approximately 0° to 90°. Each groove 20 also has a downhole angle 30, which is the angle between a downward face of the groove 20 and an upward face of an adjacent groove 20. In some embodiments, the downhole angle 30 is between approximately −75° to 180°. In various embodiments, the downhole angle 30 is between approximately 15° and 90°. It will be appreciated that the downhole angle 30 and the uphole angle 32 may not represent an angle from a flat surface since the downward face and the upward face of a groove 20 are not necessarily flat surfaces. For example, the downward face and the upward face may have a curved shape when viewed from a cross-sectional view or any other shape described herein. The downward or upward face from which a downhole or uphole angle 30, 32 is measured may be a midpoint of the face, a mean slope of the face, a median slope of the face, a mode shape of the face, etc.

Now referring to FIGS. 7A and 7B, perspective views of a casing 2 with a plurality of gripping features 4 are provided wherein a gripping feature 4 comprises multiple pluralities of grooves. Similar to the embodiment described in FIGS. 2A and 2B, the plurality of gripping features 4 in FIGS. 7A and 7B are equally spaced along the inner surface 6 of the casing 2, and the casing's inner surface 6, outer surface 8, or both surfaces 6, 8 may comprise one or more gripping features 4.

Now referring to FIG. 8, a cross-sectional view of a casing 2 with a plurality of gripping features 4 is provided wherein a gripping feature 4 comprises multiple pluralities of grooves. Similar to the embodiment described in FIG. 3, the casing 2 in FIG. 8 may have a variety of dimensions including an overall length 10 and an outer diameter 12. The dimensions described in reference to the embodiment in FIG. 3 are incorporated herein with respect to the casing 2 in FIG. 8.

Now referring to FIG. 9, a cross-sectional view of the casing 2 and the gripping feature 4 is provided wherein the gripping feature comprises multiple pluralities of grooves 20. Similar to the embodiment described in FIG. 5, the casing in FIG. 9 has an inner diameter 22 and a drift diameter 24. The aspects of these diameters 22, 24 described in reference to the embodiment in FIG. 5 are incorporated herein with respect to the casing 2 in FIG. 9.

The multiple pluralities of grooves 20 in FIG. 9 are configured in a criss-crossing pattern. A first plurality of grooves 20 is oriented along a first angle 34 relative to a lateral plane through the casing 2. Similarly, a second plurality of grooves 20 is oriented along a second angle 36 relative to a lateral plane through the casing 2. In this embodiment, the first angle 34 is approximately −45°, and the second angle 36 is approximately 45°. Thus, the first and second pluralities of grooves are substantially perpendicular to each other. It will be appreciated that in some embodiments, the first angle 34 is between approximately 0° and −90°, and in some embodiments, the second angle 36 is between approximately 0° and 90°. In addition, the gripping feature may simply include one plurality of grooves 20 or more than two pluralities of grooves 20.

Now referring to FIGS. 10 and 11, perspective views of a casing 2 with a plurality of gripping features that are grooves and a casing 2 with a plurality of gripping features that comprise multiple pluralities of grooves are provided. These views show an exemplary end finish for a casing 2, which in this case allows one end of one casing 2 to nest within another end of another casing 2. Then, a setting device or a hanging mechanism may be utilized to expand the outer diameter of the smaller casing or liner into the inner diameter of the larger casing or liner to create an interference fit.

Now referring to FIG. 12, a flow chart for a quality assurance process is provided. First, there is optimization of nominal values utilized to design gripping features via a base quality assurance and quality control process, which is customizable to specific requirements. To begin 38 the quality assurance and quality control process, materials are received 40 for creating a casing in accordance with embodiments of the present invention. The casing is purchased 42 using a customer's specification or the customer supplies the casing. Next, the casing is surveyed 44, meaning the casing is surveyed 46 at every groove pad location to determine the wall thickness at each location. Then, the maximum allowable groove depth is determined 48. The maximum groove depth may be governed by 50 a predetermined standard, for example, the API Specification 5CT requirements for minimum wall thickness of a casing.

Once the maximum groove depth is determined 48, the depth is compared 52 to the customer's required groove depth to determine whether the customer's required groove depth can be used. If yes, then drawings and specifications for the casing are created 54 for manufacturing grooves on the casing. If not, the customer determines 56 whether the shallower groove depth of the predetermined standard is acceptable. If yes, then drawings and specifications for the casing are created 54 for manufacturing grooves on the casing. If not, then the casing is returned 58 to the supplier or the customer and a new casing is requested and received 40.

After the drawings and specifications are created 54, the casing is sent 60 to a manufacturer for groove cutting. Then, gripping features are added through a mechanical process, a chemical process, any other process discussed elsewhere herein or otherwise known in the art at intervals dictated by the specific requirements. Furthermore, a lip-catch may be integrated into the wall of the casing to meet the tolerance of governing bodies or those uniquely requested. Then, the processed casing is received 62 from the manufacturer. A post manufacturing survey is conducted 64 to repeat 66 the initial survey at grooved locations to verify that the API Specification 5CT minimum wall thickness of the casing has not been exceeded.

If the processed casing does not meet API Specification 5CT standards, then the customer is alerted 70 and the casing is scrapped. If the processed casing meets API Specification 5CT standards, then the casing is marked 72 and packaged for shipment, which completes 74 the quality assurance and quality control process. A strict quality assurance and quality control process overcomes the variance allowed by current governing body guidelines, minimize or eliminate movement of anchoring systems, provide customization based on anchoring device to be utilized, and provide assurance of a secure engagement between two casings.

The invention has significant benefits across a broad spectrum of endeavors. It is the Applicant's intent that this specification and the claims appended hereto be accorded a breadth in keeping with the scope and spirit of the invention being disclosed despite what might appear to be limiting language imposed by the requirements of referring to the specific examples disclosed.

The phrases “at least one”, “one or more”, and “and/or”, as used herein, are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B, and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B, or C,” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B, and C together.

Unless otherwise indicated, all numbers expressing quantities, dimensions, conditions, and so forth used in the specification, drawings, and claims are to be understood as being modified in all instances by the term “about.”

The term “a” or “an” entity, as used herein, refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein.

The use of “including,” “comprising,” or “having,” and variations thereof, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Accordingly, the terms “including,” “comprising,” or “having” and variations thereof can be used interchangeably herein.

It shall be understood that the term “means” as used herein shall be given its broadest possible interpretation in accordance with 35 U.S.C., Section 112(f). Accordingly, a claim incorporating the term “means” shall cover all structures, materials, or acts set forth herein, and all of the equivalents thereof. Further, the structures, materials, or acts, and the equivalents thereof, shall include all those described in the summary of the invention, brief description of the drawings, detailed description, abstract, and claims themselves.

The foregoing description of the invention has been presented for illustration and description purposes. However, the description is not intended to limit the invention to only the forms disclosed herein. In the foregoing Detailed Description for example, various features of the invention are grouped together in one or more embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate preferred embodiment of the invention. Consequently, variations and modifications commensurate with the above teachings and skill and knowledge of the relevant art are within the scope of the invention. The embodiments described herein above are further intended to explain best modes of practicing the invention and to enable others skilled in the art to utilize the invention in such a manner, or include other embodiments with various modifications as required by the particular application(s) or use(s) of the invention. Thus, it is intended that the claims be construed to include alternative embodiments to the extent permitted by the prior art. 

What is claimed is:
 1. A system for hanging a casing in a borehole operation, comprising: a first casing having a wall thickness and an inner surface defining a first partially enclosed volume, said inner surface of said first casing having a gripping feature, wherein said gripping feature extends around at least a portion of an inner perimeter of said inner surface; a second casing having an outer surface with an initial diameter, said second casing is at least partially disposed within said first partially enclosed volume defined by said inner surface of said first casing, wherein said second casing has an inner surface defining a second partially enclosed volume; and a setting tool at least partially disposed within said second partially enclosed volume, said setting tool adapted to expand at least a portion of said outer surface of said second casing to a final diameter that is larger than said initial diameter, wherein said outer surface of said second casing presses against said gripping feature to secure said second casing to said first casing.
 2. The system of claim 1, wherein said inner surface of said first casing comprises a plurality of gripping features.
 3. The system of claim 1, wherein said gripping feature comprises a plurality of grooves that extend around at least a portion of said inner perimeter of said inner surface of said first casing.
 4. The system of claim 3, wherein said plurality of grooves comprises a groove density, wherein said groove density is between approximately 0.394 grooves per cm and 15.74 grooves per cm.
 5. The system of claim 3, wherein a groove of said plurality of grooves comprises a groove depth, wherein said groove depth is between approximately 0.0508 cm and 0.508 cm.
 6. The system of claim 3, wherein a groove of said plurality of grooves comprises a downhole angle, wherein said downhole angle is between approximately 15° and 90°, wherein a groove of said plurality of grooves comprises an uphole angle, and wherein said uphole angle is between approximately 0° and 90°.
 7. The system of claim 1, wherein said second casing is a liner.
 8. The system of claim 1, wherein said gripping feature has a length along the longitudinal direction of said inner surface of said first casing, wherein said length of said gripping feature is between approximately 0.635 cm and 1219.2 cm.
 9. The system of claim 1, wherein said gripping feature is a first plurality of grooves and a second plurality of grooves that extend around at least a portion of said inner perimeter of said inner surface of said first casing and form a criss-crossing pattern.
 10. The system of claim 9, wherein said first plurality of grooves is oriented at an angle relative to said second plurality of grooves, and wherein said first plurality of grooves is oriented perpendicular to said second plurality of grooves.
 11. A method for hanging a tubular in a borehole operation, comprising: providing a first tubular having an inner surface with an inner diameter, wherein a plurality of grooves is positioned on said inner surface of said first tubular; providing a second tubular having an outer surface and an inner surface, said outer surface having an outer diameter and said inner surface having an inner diameter, wherein said outer diameter of said second tubular is smaller than said inner diameter of said first tubular; positioning said second tubular at least partially within said first tubular such that said plurality of grooves are positioned over said outer surface of said second tubular; and pressing a setting tool, which has an outer surface with an outer diameter that is larger than said inner diameter of said second tubular, into said second tubular to deform said second tubular and expand at least a portion of said outer diameter of said second tubular into said plurality of grooves of said first tubular to secure said second tubular to said first tubular.
 12. The method of claim 11, wherein each groove in said plurality of grooves has an uphole angle and a downhole angle measured from a lateral plane through said first tubular, and wherein said downhole angle is nonzero.
 13. The method of claim 12, wherein at least one groove in said plurality of grooves has one of a distinct uphole angle and a distinct downhole angle from another groove in said plurality of grooves.
 14. The method of claim 11, wherein said plurality of grooves comprises a groove density, wherein said groove density is between approximately 0.394 grooves per cm and 15.74 grooves per cm.
 15. The method of claim 11, wherein said plurality of grooves extends around an inner perimeter of said inner surface of said first tubular.
 16. A tubular for a borehole operation comprising: a body extending between a first end and a second end, said body having an inner surface; a first finish on said first end of said body; a second finish on said second end of said body, wherein said second finish is distinct from said first finish; and a plurality of grooves positioned on said inner surface of said body, each groove in said plurality of grooves having an uphole angle and a downhole angle measured from a lateral plane through said body, wherein said downhole angle is nonzero.
 17. The tubular of claim 16, wherein at least one groove in said plurality of grooves has one of a distinct uphole angle and a distinct downhole angle from another groove in said plurality of grooves.
 18. The tubular of claim 16, wherein said plurality of grooves comprises a groove density, wherein said groove density is between approximately 0.394 grooves per cm and 15.74 grooves per cm.
 19. The tubular of claim 16, wherein said plurality of grooves extends around an inner perimeter of said inner surface of said first tubular.
 20. The tubular of claim 16, further comprising: a second plurality of grooves positioned on said inner surface of said body. 